Breech loading gun



April 19, 1932. D. GOBBO BREECH LOADING GUN Filed Nov, 13, 1931 Patented Apr. 19, 1932 Pahi? DOMENICO GOBBO, F TREN, ITALY BREECH LOADING GUN Application filed November 13, 1931, Serial No. 574,821, and in Italy November 14, 1930.

This invention relates to a closing device for fire arms, more particularly for semiautomatic fire arms with recoiling barrel for firing as repeating arms. The characteristic a feature of this device consists in the fact that the striker is only capable of rectilinear movement and one compression spring, acton a key mounted in a cross slit on the striker causes the breech bolt to perform the feed and closing stroke, the final forward motion of the striker being effected only when the breech bolt is perfectly closed and being caused by a suitable cock.

According to this invention the key fitted in the cross slit on the striker projects on both sides of this latter and its projecting front portions end by a helical (or inclined) surface, which by coming into contact with a corresponding helical surface formed on :in the breech bolt rotates this latter to its closed position as soon as the breech bolt has reached the end of its arial forward stroke and the shank of the handle has escaped from the rectilinear guide slit on the fra-me and '5 reaches a corresponding notch which enables the breech bolt to rotate and to reach its locked position. When this rotation is completed the projecting portions of the key rest against the corresponding helical surfaces of the breech bolt, which, having reached the end of its stroke, stops the key and retains the return spring preventing any further release of this latter. The arrangement is such that at this moment the striker on which no further pressure is exerted by the return spring is free to perform a short forward motion allowed by a certain play of the key in the slit on the striker and by the mounting of the striker in the breech bolt, sufficient il* for the striker pin to project into the cartridge chamber. The slight frictions of the parts of the key cooperating` with the striker are sufficient for retaining this latter until it is acted upon by the cock for performing '-5 the firing stroke.

The accompanying drawings show, by wav of example, a construction of the object of this invention.

Figures 1 and 2 are two sectional views at right angles to each other in the position in which the breech bolt is closed but the striker has not yet performed its firing stroke.

Figure 3 is a cross section in the closed position.

Figures l and 5 show the key and Figure 6 shows the striker.

Gn the drawings, 1 denotes the frame of the weapon, 2 denotes the breech bolt which is guided in a rectilinear longitudinal slit 6 on the frame by the shank 6 of the handle 7: till the end of the forward stroke, and which can effect an angular rotation from the position 7 to the position 'Y'1 of Fig. 3, when it has reached the end of this stroke, whereupon it is received by a corresponding notch 6 on the frame. 3 denotes the striker provided with a too-th 8, through which it is guided in a rectilinear direction and kept from turning in a longitudinal groove 9 on the frame. The breech bolt 2 is provided at 'i0 its front end with closing wings l adapted to engage in corresponding seats on the barrel 5.

The weapon shown is of the type with recoiling barrel. -7 5 The striker is provided with a cross slit 1() in which a key 11 is lodged and acted upon directly by the return spring 12 which works only by compression. The key 11 projects on both sides of the striker as shown in Fig. 2, and its projecting portions end by front helical surfaces 111 adapted to co-operate with corresponding helical surfaces formed in the chamber 13 of the breech bolt on an angular width equal to the width of therotation of the breech bolt to its locked position.

rlhe working of the device is as follows:

During the forward stroke, after the recoil, the return spring 12 acts on the key 11 and this pressure is transmitted to the bre-ech bolt which is moved forward on its feeding stroke. At the end of this rectilinear movement, the breech bolt is no longer retained by the rectilinear guide slit 6 and the helical surfaces 111 of the key, which transmit the pressure of the spring 12 to the corresponding helical surfaces of the breech bolt, rotate this latter toits locked position, the key and the striker being kept from turning.

bolt, while the striker effects a further short forward -movement allowed by the greater width of its cross slit with respect to the key fitted therein and by the space still free between the striker head and the bottom of the breech bolt chamber in which it is 4 Ymounted.

The striker is retained in its position merely by the friction of the parts, as the return spring no longer acts thereon. The cock (not shown) then causes the rapid forward movement of the striker by a small extent suiiicient for causing its pin 14 to project into the cartridge chamber 15 for firing. The

cock acts through a suitable slit 17 on the frame on the rear face of the tooth 8 of the striker.

The breech bolt is provided on its rear Vportion with a notch 16 with inclined bottom receivingthe tooth 8 of the striker large enough for` permitting the rotation of the breech bolt while the striker is prevented from turning.

The inclination of the bottom of the notch 16 .is made such that at the end of the rotation the front inclined portion of the tooth 8 is situated a short distance from the said `inclined bottom for enabling the striker to perform its final firing stroke. This arrange- `rment provides forl an auxiliary safety against any untimely forward motion of the striker. 'The recoil stroke, following firing, is effected in the usual manner and the usual neans employed in fire arms are used there- What I claim is: l1. In a fire arm, the combination with a barrel and a frame, of a breech bolt movably mounted in said frame, a striker slidable in an axial hole of said breech bolt, a tooth on said' striker engaging in a longitudinal groove on the frame for preventing the rotation of the striker, a return spring acting on the striker and the breech bolt for effecting the feed and closing stroke of the breech bolt and means interposed between said striker and said spring for effecting the locking movement of the breech bolt and at the same time releasing the striker from the action of said spring.

Y2. In a fire arm the combination with a barrel and a frame at the rear end of said barrel, of a breech bolt movably mounted in said frame, a member on the breech bolt engaging in a longitudinal slit cut on the frame and endingv at itsfront end into a helical slit for permitting the locking movement of the breech bolt, a striker slidable in an axial hole in said breech bolt, a tooth on said striker en-V gaging in a longitudinal groove on the frame 1 a key lodged 1n a cross slit on the striker and for preventing the rotation of the striker projecting at both ends into a breech bolt chamber, inclined surfaces on the front por- 't nal direction, smaller than that of the slit 4in which it is fitted, so that when the breech bolt is rotated to its, locked position under the action of said inclined planes and of said spring, this latter `acts bolt through the key, while .the striker is free to move by an extent corresponding to the play between said key and its seatv inthe striker. Y

In testimony whereof I hereunto affix-.my

signature.

DOMENICO GOBBO. Y

lsolely onV the breech 

